This patent document relates to optical devices that guide and manipulate light.
An optical lens is a fundamental optical component or device of various optical devices for guiding and/or manipulating light. Optical lenses can be made of optical dielectric materials shaped to have one or more contiguously smooth concave or convex shapes that use concave or convex surfaces to guide or manipulate light by optical refraction. Such lenses can be designed to control light with high precision and can be configured as, for example, high quality imaging lenses used in optical imaging capturing devices (e.g., cameras) and image display systems (e.g., projectors). An optical lens can also be made of a dielectric material shaped to have a set of discrete, concentric annular rings known as Fresnel zones to achieve large optical apertures.
Optical lenses based on the above designs tend to be limited in various aspects due to certain characteristics of natural or synthetic optical dielectric materials such as limited upper values and the positive sign of refractive indices, or other requirements of certain applications such as requirements on the physical size or weight of optical devices.